Tan, Y. orcid.org/0000-0002-5207-8753, Gardner, L.J. orcid.org/0000-0003-3126-2583, Walkley, B. orcid.org/0000-0003-1069-1362 et al. (5 more authors) (2023) Optimization of magnesium potassium phosphate cements using ultrafine fly ash and fly ash. ACS Sustainable Chemistry & Engineering, 11 (8). pp. 3194-3207. ISSN 2168-0485
Abstract
The effect of ultrafine fly ash (UFA) and fly ash (FA) on the physical properties, phase assemblage, and microstructure of magnesium potassium phosphate cement (MKPC) was investigated. This study revealed that the UFA addition does not affect the calorimetry hydration peak associated with MKPC formation when normalized to the reactive components (MgO and KH2PO4). However, there is an indication that greater UFA additions lead to an increased reaction duration, suggesting the potential formation of secondary reaction products. The addition of a UFA:FA blend can delay the hydration and the setting time of MKPC, enhancing workability. MgKPO4·6H2O was the main crystalline phase observed in all systems; however, at low replacement levels in the UFA-only system (<30 wt %), Mg2KH(PO4)2·15H2O was also observed by XRD, SEM/EDS, TGA, and NMR (31P MAS, 1H-31P CP MAS). Detailed SEM/EDS and MAS NMR investigations (27Al, 29Si, 31P) demonstrated that the role of UFA and UFA:FA was mainly as a filler and diluent. Overall, the optimized formulation was determined to contain 40 wt % fly ash (10 wt % UFA and 30 wt % FA (U10F30)), which achieved the highest compressive strength and fluidity and produced a dense microstructure.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023 The Authors. Published by American Chemical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | magnesium potassium phosphate cement; fly ash; characterization; particle size distribution |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Chemical and Biological Engineering (Sheffield) The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/N017617/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/P013600/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/S032959/1 Engineering and Physical Sciences Research Council EP/T011424/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 Mar 2023 11:58 |
Last Modified: | 06 Mar 2023 11:58 |
Published Version: | http://dx.doi.org/10.1021/acssuschemeng.2c04987 |
Status: | Published |
Publisher: | American Chemical Society (ACS) |
Refereed: | Yes |
Identification Number: | 10.1021/acssuschemeng.2c04987 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:197038 |